(Reuters) - The U.S. Food and Drug Administration said on Friday it has approved Novartis AG's drug Afinitor to treat women with a certain type of breast cancer.

The drug is the first in a class known as mTOR inhibitors to be approved for post-menopausal women with advanced hormone-receptor positive, HER2-negative breast cancer.

Afinitor, also known as everolimus, is designed to be given in combination with another drug, Aromasin, to treat women whose cancer has recurred or progressed after treatment with two other therapies.

A late-stage trial showed that patients who received Afinitor plus Aromasin had a 4.6 month improvement in the median time to disease progression or death over those receiving Aromasin plus a placebo, the FDA said.

Afinitor is already approved to treat patients with certain other types of cancer.